A service has been known which is called “public wireless LAN” that enables an internet connection using a wireless LAN (local area network) with the use of a communication terminal brought by a user in restaurants or stations. In this connection service, an electric wave of the wireless LAN is leaked out of an area to which the service is to be provided, and the service may be utilized by an unintended user. For example, Patent Literature 1 discloses that, in order to restrict an area to which configuration information is distributed, an access point blinks an infrared LED light emitting unit, and a digital camera of a communication device picks up the blinked light emitting unit, whereby the communication device obtains the configuration information necessary for connection to the access point.